For the Rubik's cube I copied the files in zenoclash\zenozoik\models\props\rubik\ to garrysmod\garrysmod\models\props\rubik\ (I created the folder).Then I copied my converter into the same folder as rubik.vvd (in the garrysmod folder) and converted the .vvd file.Then I copied zenoclash\zenozoik\materials\models\props\rubik.vmt, zenoclash\zenozoik\materials\models\props\rubik.vtf, zenoclash\zenozoik\materials\models\props\rubik_ex.vtf and zenoclash\zenozoik\materials\models\props\rubik_local.vtf to garrysmod\garrysmod\materials\models\props (I created the folder).Then in-game I spawned it using the Browse part of the spawn menu.